Lube & Auto is merging with Gianni Cosmetics and the deal characteristics are presented below:

Lube & Auto Gianni Cosmetics

Firm Value $$100$ $$150$

Debt Face Value $$80$ $$50$

Debt Maturity $1010$

St$.$ Dev. Firm Value $40\mathrm{.}00\%50\mathrm{.}00\%$

Share of assets in survivor $0\mathrm{.}40\mathrm{.}6$

Correlation b$/$n CFs $0\mathrm{.}1$

Option Price Values

Equity Value in Firm $$75\mathrm{.}90$ $$134\mathrm{.}50$

Debt Value in Firm $$24\mathrm{.}10$ $$15\mathrm{.}50$

$($a$)$ Please calculate the value of equity and the value of debt for the combined firm.

$($b$)$ Please calculate the debt yield